There are a few differences, but as new data emerges, the differences may eventually turn out to be fewer and less significant between the two groups. Right now, the major differences include:
• The atypicals act on a number of neurotransmitter systems, not just dopamine (this appears to also be true for the older medication loxitane (Loxapine)).
• The side effect profiles between the two groups of medications shows that typicals are more likely to cause extrapyramidal symptoms (symptoms that can mimic Parkinson’s disease and cause other movement abnormalities).
• The typical antipsychotics are more likely to cause tardive dyskinesia, a potentially irreversible movement abnormality. The rate of tardive dyskinesia with the newer medications has not yet been fully evaluated, but appears to be less.
• The atypicals are more associated with a metabolic syndrome that is characterized by weight gain, an increase in abdominal girth, elevated cholesterol and lipids, and type II diabetes mellitus.